I've got a pair of AKG K271 MK2 Studio, and they are excellent.They are the most comfortable headphones I've used...I can have them on for hours on end without the slighest discomfort.They are a little bit heavy on the bass side though, so if you're looking for a very flat sound, they're not the ones for you.I use them mainly for drumming (e-kit) nowadays, but I used them with my now dust-collecting Pod HD500 and they were great for that.

I also got a pair of AKG K140 (I think anyway..) and they are about as good, they're not covered though, so they bleed quite a bit of sound.

If isolation is not an issue, (ie you have no roommate that gets bothered) then try Alessandro headphones. Made by Grado labs to Alessandros design. Very neutral sound. I owned MS-1 model for quite some time, worth every penny.

If you have a roommate, then open headphones are not an option. You need closed ones. Unfortunately my experience with them is low. Only one I own is Ultrasone Proline 750 (aka Pro750 nowadays), and thats beyond your price range. It also has quite strong bass so you might not like it.